Inorg. Chem. 1983, 22, 1 168-1 174
1168 C1112AI
GI12
F m 4. Projection of the Os3gl-H)3(CO)9(SiC13)3molecule, showing the atom-labeling scheme. Both sets of disordered chlorine atoms about Si( 1) are shown. Hydrogen atoms are drawn as small spheres at their calculated positions. present in the same crystal: in one, each methyl group was on the side of the OsHOs bridge, and in the other, each was on the side of the in-plane carbonyl.* It is interesting that in the present structure, within an individual molecule, the corresponding in-plane chlorine substituent of one silicon ligand
is on the side of the OsHOs bond and in a second it is on the side of the in-plane carbonyl, while in the third, it is disordered between the two positions. The Os-SiC1, distances measured in the two structural determinations reported here are not significantly different: 2.377 (3) A in O S , ( C O ) , ~ ( S ~ C and ~ , ) ~a mean value of 2.383 A in Os,H3(C0)9(SiC13)3. These lengths are slightly shorter than the Os-Si bond lengths in O S , H ~ ( C O ) ~ ( S ~ M ~(mean C~~), value 2.410 A) although the difference is barely significant. This, as discussed previously, may indicate more double-bond character in the Os-SiC1, linkage. The osmium-osmium vectors (mean 3.129 A) found in OS,H,(CO)~(S~C~,)~ are virtually identical with those found in one conformer of O S ~ H , ( C O ) ~ ( S ~ M ~(3.125 C ~ ~ (2) ) , A); the other conformer had slightly longer Os-Os bonds (3.155 (2) A). As previously stated, these are among the longest distances determined for such bonds.* We are continuing the investigation of silanes with various osmium clusters.
Acknowledgment. We are grateful to the Natural Sciences and Engineering Research Council of Canada for financial support. We also wish to thank Professor W. A. G . Graham and Dr. W. A. Whitla for details of the structure of Fe(Co)4(sic13)2. Registry No. A, 84750-97-0; B, 79329-41-2; Os3(C0)12(SiMeC12)2, 84750-98-1; O~,(C0)12,15696-40-9; OS, 7440-04-2. Supplementary Material Available: Listings of anisotropic thermal parameters and observed and calculated structure factors for A and B (24 pages). Ordering information is given on any current masthead page.
Contribution from the Departments of Chemistry, Faculty of Science, Osaka City University, Sumiyoshi-ku, Osaka 558, Japan, and Faculty of Science, Tohoku University, Aoba, Aramaki, Sendai 980, Japan
Crystal Structures of VIv, Vv, and VIVVv Complexes of the ( S ) - [1-(2-PyridyI)ethyl]imino]diacetate [ Ion. Comparison of the Molecular Structure of the Binuclear Mixed-Valence VIVVv Complex with Those of Constituent VIv and Vv Complexes AKINOBU KOJIMA,ln KENICHI OKAZAKI,lb SHUN'ICHIRO OOI,*la and KAZUO SAITOIb
Received April 28, 1982 The crystal structures of [VO(S-peida)(H20)]-2H20( l ) , Na[V203(S-peida)2]-NaC104.H20 (2), and Li[VO,(S-pei[ 1-(2-pyridyl)ethyl]imino]da)].2CH30H (3) have been determined by single-crystal X-ray diffraction (S-peida2-, (S)-[ diacetate). Every vanadium atom in 1-3 has an octahedral coordination with a donor atom disposition similar to the others: the axial sites are occupied by 02-and N (tertiary), and there are two 0 (OOC), one N (pyridine), and one L (L = H 2 0 in 1; L = 02-in 2 and 3) in the equatorial sites. The two coordination octahedra in the mixed-valence binuclear [V203(S-peida)2]-are linked together by sharing the equatorial 02-(ob) ligand. The o = v A - o b - v ~ = o segment in = 179.5 (3)O; the torsion angle between the two V - 0 bonds the dimer has an approximate trans-planar structure (V+-V is 164.3 (2)'). The v A + , bond (1.875 (4) A) differs significantly from the VB-0, bond (1.763 (4) A) in length, and furthermore, the volumes of the coordination octahedra around V, and VBare close to those of 1 (Vw) and 3 (V"), respectively: i.e., VA and VB are inequivalent. These structural features indicate that the mixed-valence dimer should be classified as a class I1 ion; however, the reflectance spectrum of 2 in the 9000-20000-~m-~region resembles that of (NH4),[V203(nta),]-3H2O, in which the anion is known to be a class I11 ion (nta3- = nitrilotriacetate). Crystal data: 1, space group P21, a = 7.707 (3) A, b = 11.608 (3) A, c = 8.802 (6) A, j3 = 91.84 (3)O, 2 = 2; 2, space group El,a = 12.680 (5) A, b = 15.273 (6) A, c = 7.856 (3) A, j3 = 98.25 ( 6 ) O , 2 = 2; 3, space group P212121,a = 19.387 (2) A, b = 10.259 (1) A, c = 8.645 (1) A, 2 = 4. The structures were refined by least squares to R = 0.041, 0.040, and 0.034 for 1, 2, and 3, respectively, with 2013, 2971, and 1871 reflections [F2 > 3u(F2)].
Introduction Coordination chemistry of early transition metals has been drawing increasing attention of chemists, but available structural d a b are much more limited as compared with those (1) (a) Osaka City University. (b) Tohoku University.
of the other transition elements. During the kinetic study of oxovanadium(IV) complexes we have found the new mixedvalence complex [ V ~ 0 3 ( n t a ) ~(nta3] ~ - = nitrilotriacetate), in which the two v atoms are linked linearly with the oxide.2 We (2) Nishizawa, M.; Hirotsu, K.; Ooi, S.; Saito, K. J . Chem. Soc., Chem. Commun. 1979,111.
0020-1669/83/1322-1168$01.50/00 1983 American Chemical Society
Inorganic Chemistry, Vof.22, No. 8, 1983 1169
V Complexes of [ [ 1-(2-Pyridyl)ethyl]imino]diacetate Table I. Crystal Data and Experimental Details compd
[VO(S-peida)(H, 0 )1. 2H,O
color ~...~
blue
formula
vc
fw
space group cell const a, A
b, A c, '4
P , deg
Z p(obsd), g cm-) p(calcd), g cm-3 cryst dimens, mm3 p, cm-' transmission coeff limits scan mode scan speed, deg s - l scan range in w, deg bkgd estimation at each end of the scan. S 28max* deg unique data measd obsd reflectns used [F,' > 30(Foz)] R R, = [ . Z W A ~ / ~ W F ~ ~ ] ~ ' ~
-
Na [V, 0, (S-peida), 1. NaClO,.H, . -0
Li[ VO ,(S-peida)]. 2CH,OH
dark blue
vellow
p2 I
p21212,
12.680 (5) 15.273 (6) 7.856 (3) 98.25 (6) 2 1.72 1.73 0.35 X 0.24 X 0.21 8.62 1.17-1.25
19.387 (2) 10.259 (1) 8.645 (1)
H I 8 NZO 8 357.09
R
II
I
7.707 (3) 11.608 (3) 8.802 (6) 91.84 (3) 2 1.51 1.51 0.33 X 0.24 X 0.12 7.1 1 1.09-1.18 W-2e 0.025 1.oo half of scan time 60.0 21 23 201 3 0.041 0.042
now succeeded in preparing new optically active complexes [ of VIv, VIVVv and Vv by use of ( S ) - [ 1-(2-pyridyl)ethyl]iminoldiacetate (S-peida2-). This paper deals with the detailed description of X-ray structures of [V1vO(S-peida)(HzO)]. (2), and 2 H 2 0 (l),Na[V1VVV03(S-peida)2]~NaC104.H20 Li[VV02(S-peida)]*2CH30H (3) and discusses characteristic features of the mixed-valence complex in comparison with those of the VOz+ and V 0 2 + complexes.
(3) Okazaki, K.; Saito, K. Bull. Chem. SOC.Jpn., in press. (4) Hornstra, J.; Stubbe, b. "PW1100 Data Processing Program"; Philips Research Laboratories: Eindhoven, Holland. ( 5 ) Templeton, L. K.; Templeton, D. H.; Abstracts, American Crystallographic Association Proceedings, 1973; Series 2, Vol. 1.
1.51 0.30 X 0.30 X0.15 6.58 w-2e 0.025 0.9 + 0.3 tan 0 20 55.0 2306 1871 0.034 0.040
w
0.033 1.40 20 55.0 3615 2971 0.040 0.049
Table 11. Positional Parameters (X l o 4 ) for [ VO (9 peida)(H 0)I *2H 0 ( 1)
,
Experimental Section The preparation of the compound will appear in a separate paper.' X-rayData Collection. Weissenberg and precession photographs taken with Cu K a radiation were used for investigating Laue symmetry, space group, approximate unit-cell dimensions, and Miller indices for the bounding surfaces of the crystal. The accurate cell dimensions were determined from the least-squares treatments of 24 (l),22 (2), and 44 (3) 8 values of higher angle reflections (16" < 28 < 30") measured on a Philips P W l 100 diffractometer by use of Mo Ka radiation (A = 0.71069 A). Since compound 3 is very hygroscopic, the crystal specimen was sealed within a thin-walled Lindemann glass capillary for use. Crystal data are given in Table I. Intensities were measured on the diffractometer using graphitemonochromated Mo K a radiation a t room temperature (Table I). Stationary-crystal, stationary-counter background counts were measured a t each end of the scan. For every crystal the intensities of three standard reflections (200,020,002 for 1; 200,020, 001 for 2; 600, 060, 002 for 3) were monitored every 4 h, but they showed no appreciable decay during the data collection. The intensity data were processed by the computer program of Hornstra and Stubbe4 by use a value of p = 0.04. Absorption correction was applied to the data of 1 and 2 by using the program written by Templeton and Templeton.s Solution and Refnement of Structures. The crystal structures were solved by the Patterson-Fourier method. The positional and thermal parameters were refined by a block-diagonal-matrix least-squares method. The minimized function was xw(lF,,I - IFcl)z,where w = d(FO)-l, The convergence was attained with R and R, = [x.w(lFol - I F c l ) z / C w F ~ ] 1values / 2 listed in Table I. Except for H atoms of the methyl group, the H atoms of the complex ion/molecule were located in the idealized positions (C-H= 0.95 A). They were in the proximity of the peak positions on the difference Fourier map cal-
4
atom
X
Y
z
V O(1) O(2) 00) O(4) O(5) 0(6) NU) N(2) C(1) C(2) C(3) C(4) C(5) C(6) C(7) C(8) C(9) C(10) C(11) 0,U) 0,m
3084 (1) 3050 (6) 3395 (3) 593 (3) -2002 (3) 5366 (3) 3588 (4) 2558 (4) 1874 (3) 2517 (6) 2227 (7) 1985 (7) 2011 (6) 2311 (4) 2488 (5) 2499 (6) 2995 (5) -35 (4) -529 (4) 1598 (8) 7133 (4) 3748 (5)
0 2748 (3) 1036 (2) -134 (3) 673 (3) 661 (3) -1282 (3) -279 (2) 1673 (3) -1347 (4) -1531 (4) -608 (5) 500 (4) 638 (3) 1807 (3) 2591 (4) 21 14 (4) 1537 (3) 641 (4) 2786 (4) 83 (4) -4289 (4)
4893 (1) 2099 (3) 3141 (3) 4167 (3) 3816 (3) 5668 (3) 4399 (4) 7199 (3) 5747 (3) 7794 (5) 9326 (5) 10231 (5) 9634 (4) 8099 (4) 7364 (4) 4745 (4) 3198 (4) 5600 (4) 4418 (4) 8193 (5) 8086 (3) 9035 (4)
culated after the refinement of the structure using anisotropic thermal parameters for non-hydrogen atoms. The methyl, methanol, and water hydrogen atoms were located on the peaks revealed on the difference map. These H atoms were included in the least-squares calculation, but their positional and thermal parameters (B = 5.0 A*) were fixed. No secondary extinction correction was applied. Final difference syntheses for 1-3 showed no anomalous features. Atomic scattering factors for Vo,Cl0, Na+, Li', 0, N, C, and H, with corrections for anomalous dispersion effects for and Cl0, were taken from ref 6. Tables of observed and calculated structure factors and the hydrogen atom coordinates are available as supplementary material. Computational work was carried out by using standard programs.' Spectral Measurement. The reflectance spectra of powder crystals were recorded with a Hitachi 330 spectrometer with a 604 integrating sphere attachment (210-21 01 ) . "International Tables of X-ray Crystallography";Kynoch Press: Birmingham, England, 1974; Vol. IV. (7) 'UNICS", Crystallographic Society of Japan, 1969. Johnson, C. K. 'ORTEP II", Report ORNL-5138; Oak Ridge National Laboratory: Oak Ridge, TN, 1976. (6)
Kojima et al.
1170 Inorganic Chemistry, Vol. 22, No. 8, 1983
Table 111. Positional Parameters (X l o 4 ) for Na[ V,O, (S-peida), ].NaClO ,.H,O(2) X Y atom 1450 (1) 2575 (1) -11 (3) 292 (3) 1022 (4) 780 (4) 944 (3) 2021 (3) -528 (4) 1211 (3) 2988 (3) 2477 (3) 3355 (4) 3011 (4) 2183 (3) 3616 (4) 1696 (4) 3322 (5) 4359 (6) 5066 (6) 4762 (5) 3732 (5) 3349 (5) 1636 (5) 564 (5) 1974 (5) 1187 (5) 4015 (5) 4636 (5) 5272 (6) 4849 (7) 3810 (6) 3192 (5) 2013 (5) 571 (5) 375 (5) 2014 (5) 2497 (5) 1680 (6) 7958 (6) 9758 (2) 8462 (2) 6854 (1) 6182 (5) 6407 (5) 7111 (7) 7893 (6)
(3) Figure 1. Perspective views of [VO(S-peida)(H20)] (l), [V203(Speida)J (2), and [V02(S-peida)]-(3). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms are shown by spheres with an arbitrary radius, but those for [V203(S-peida)z]-are omitted
for clarity. Results Figure 1 shows perspective views of [VO(S-peida)(H,O)], [V203(S-peida)2]-,and [V02(S-peida)]- as well as the atom numbering. Each vanadium atom in these complexes has a coordination geometry similar to the others with the S-peida ligand in the same conformation; the tertiary and pyridine nitrogens occupy the axial and equatorial sites of a distorted
z
0 1678 (1) -148 (3) -121 (3) -1181 (3) -2602 (3) 556 (3) 871 (3) 1849 (3) 1798 (3) 4174 2811 (3) 1127 (3)
1692 (1) 4703 (1) 5835 (5) 3157 (5) 661 (5) 1043 (6) 12 (5) 3237 (5) 4821 (6) 5640 (5) 6384 5931 (5) (5) 6115 (5)
-220 (3) -951 (3) 1980 (3) 2696 (3) 34 (5) -87 (5) -471 (5) -731 (5) -581 (4) -756 (4) -736 (4) -305 (4) -1852 (4) -1891 (4) -1408 (4) 1704 (5) 1791 (5) 2155 (6) 2431 2330 (5) (4)
1190 (6) 3794 ( 5 ) 2936 (6) 2911 (6) -336 (7) -630 (9) 582 (10) 2140 (9) 2409 (7) 4115 (7) 5293 (7) 4745 (8) 3153 (8) 1529 (8) 5281 (9) 3197 (8) 1918 (11) 354 (10) 1421 115 (8) (7)
2549 (4) 2499 (5) 2015 (4) 3572 (4) 3538
1172 (7) 2956 (8) 4564 (7) 5471 3608 (8) (7)
1332 3287 (5) (4) 1120 (2)
-106 1313 (7) (8) 7628 (3)
467 (2) 804 (1) 100 (4) 1529 (4) 1114 (5) 590 (5)
3680 (3) 6806 (2) 6555 (11) 7567 (8) 5219 (9) 7664 (12)
coordination octahedron, respectively. A common atom numbering was used throughout the three complex molecule/ions except for the 0(5),which stands for aqua, bridging oxo (Ob), and oxo ligands in 1, 2, and 3, respectively. Atomic coordinates are given in Tables 11-IV. The vanadium atom in every complex is displaced toward the apical oxo ligand O(6) from the equatorial plane defined by 0 ( 2 ) , 0 ( 3 ) , 0(5),and N(1). The deviation in 1 (0.401 A) is ty ical of a 6-coordinate V02+complex,8 and that in 3 (0.357 ) is somewhat larger than those in (NH4)3[V0,(oxalato),].2H20 (0.26, 0.29 A)9 and [VO(isopropoxo)(8A).1o In the binuclear ion the disq ~ i n o l i n a t o ) ~(0.28 ] placement of VA (0.401 A) is equal to that in 1, while that of VB (0.361 A) is close to the deviation in 3. The binuclear ion has an approximate C, symmetry, the twofold axis of which passes O b and is normal to the mean plane of the *v-ob-v+ segment. The V-0b-v bond angle is 179.5', and thus the arrangement is substantially
K
(8) Ooi, S.; Nishizawa, M.; Matsumoto, K.; Kuroya, H.; Saito, K. Bull. Chem. SOC.Jpn. 1979, 52, 452 and references therein. (9) Scheidt, W. R.; Tsai, C.; Hoard, J. L. J . Am. Chem. SOC.1971, 93, 3867. (10) Scheidt, W. R. Inorg. Chem. 1973, 12, 1758.
V Complexes of [ [ 1-(2-Pyridyl)ethyl]imino]diacetate Table IV. Positional Parameters Li[ VO (S-peida)].2CH, OH (3) atom X -863.0 (3) 496 cii -449 (1) -1657 (1) -1905 (1) -173 (1) -1409 (1) -1203 (1) -404 (1) -1733 (2) -1920 (2) -1553 (2) -1011 (2) -849 (2) -231 (2) 225 (2) 88 (2) -871 (2) -1531 (2) 48 (2) 1880 (2) 1850 (1) 2293 (3) 1452 (3) 1436 (4)
Inorganic Chemistry, Vol. 22, No. 8, 1983 1171 Table V. Bond Lengths (A)
(X l o 4 ) for
Y
Z
-147.1 (5) -1378 (3) -572 (2) -1502 (2) -3525 (3) 518 (3) 1061 (2) -717 (3) -2150 (3) -120 (4) -440 (5) -1386 (5) -201 9 (5) -1667 (4) -2200 (3) -2077 (4) -1316 (3) -3197 (3) -2705 (4) -3505 (5) -1159 (3) -1701 (3) -1627 (5) -1298 (8) -2101 (7)
1057 (1) 4193 (3) 3102 (3) 1823 (3) 2569 (4) 356 (3) 1348 (3) -1156 (4) 677 (3) -1881 (4) -3376 (5) -4147 (5) -3400 (5) -1899 (4) -1017 (5) 1642 (5) 3105 (5) 1192 (5) 1909 (4) -1573 (5) 2493 (5) -3882 (4) 1321 (7) -2675 (7) 4150 (8)
[ VO(Speida).
(H,O)l 1.602 (3) 2.018 (3) 2.010 (2) 1.977 (3) 2.108 (3) 2.292 (3) 1.344 ( 5 ) 1.511 (5) 1.493 (4) 1.525 (6) 1.289 (5) 1.530 (5) 1.474 (5) 1.218 (5) 1.273 (5) 1.511 (5) 1.482 (4) 1.238 (8) 1.347 (5) 1.390 (6) 1.352 (7) 1.389 (7) 1.388 ( 5 )
[ V 2 0 ,(S-peida), ] A
B
1.622 (4) 1.613 (4) 1.875 (4) 1.763 (4) 2.019 (4) 2.013 (4) 2.000 (4) 1.983 (4) 2.100 (5) 2.099 (5) 2.293 (4) 2.278 (4) 1.344 (7) 1.345 (7) 1.514 (8) 1.516 (8) 1.494 (7) 1.496 (7) 1.524 (8) 1.528 (8) 1.277 (7) 1.300 (7) 1.516 (8) 1.515 (9) 1.487 (7) 1.464 (7) 1.225 (8) 1.218 (7) 1.282 (7) 1.298 (7) 1.504 (8) 1.504 (8) 1.477 (7) 1.480 (7) 1.238 (8) 1.210 (7) 1.371 (8) 1.348 (8) 1.380 (10) 1.382 (11) 1.345 (10) 1.385 (11) 1.393 (11) 1.370 (11) 1.372 (9) 1.386 (10)
[VO,(S-peida)] 1.649 (2) 1.619 (2) 2.177 (2) 1.990 (3) 2.106 (3) 2.263 (3) 1.353 (5) 1.522 (5) 1.503 (5) 1.523 (6) 1.290 (4) 1.510 (5) 1.480 (5) 1.231 (5) 1.261 (4) 1.509 (5) 1.472 (5) 1.249 (5) 1.351 ( 5 ) 1.382 (6) 1.376 (7) 1.393 (6) 1.384 (6)
portion is rotated clockwise about the V+N(2) vector; the 0(3)-V-N(2)-C(9) torsion angle is 13.4 (2)'. Such a clockwise rotation is also observed in the A and B halves in 2, but the torsion angles are very small as compared with those in 1 (3.0 (4) and 4.9 (4)' in the A and B halves, respectively). Interatomic distances and bond angles are listed in Tables V and VI. The V=O length in 1 is comparable to those in [VO(pmida)(H20)] (pmida2- = [(2-pyridylmethyl)imino]diacetate) and other V02+complexes.s The axial V=O bond in 3 is 0.030 A longer than the equatorial one, but these bond lengths are not much different from those in (NH4)3[VOz(oxalat0)~]-2H~O (1.635 (2), 1.648 (2) A)9 and NH4[VOZ(edtaH2)].3H20 (1.623 (2), 1.657 (2) A)." The V=O distance in the binuclear mixed-valence complex is rather close to that in a usual V02+complex8 compared to the mean V 4 distance in V02+complexes?J1J2 The V 4 group is known to give a remarkable trans influence. In Na2[(VO),(ttha)].10H20 (tthab = triethylenetetraminehexaacetate), it was found that the trans influence makes the axial V-N(tertiary) bond 0.1 3 1 A longer than the equatorial one.l3 The axial V-N(2) distance in 1 agrees well with that in the ttha complex (2.294 (7) A) and hence must be under the influence of the apical oxo ligand. The V-OH2 distance in 1 is in agreement with those in the pmida complex (2.02 (1) A),8VOSO4.5H20 (2.006 (1)-2.019
(2) A),14and (NH4)2[VO(oxalato)2(H20)]-H20 (2.033(3) A).15 The VA-0, and VB-Ob distances in the dimer differ from each other, and the difference is significant in view of their esd's. The two vanadium atoms are thus inequivalent in the dimer. However, the mean value of V-Ob lengths (1.819 A) agrees with that in (NH4)3[V203(nta)2]-3H20 (1.810 (1) A).2 The mean v-ob distance is fairly longer than the equatorial Vv=O distance in 3 and the Vv=O(isopropoxo) length (1.774 (2) A) in the 8-quinolinato complexlo but considerably shorter than Vv-O(OOC), V'v-O(OOC), and VI"-OH2 distances.*-ls The V-N( 1) length agrees well with that in the pmida complex (2.11 (1) A) and that in the 5 coordinate VO(sa1pn) (2.1 1 (1) A)16 but is slightly shorter than the equatorial V-N(sp3) bond length in the ttha c0mp1ex.l~ The V-O(3)(OOC) bond in 3 is considerably longer than the V-0(2) bond owing to the trans influence of the in-plane oxo ligand O(5). The vA-0(3) and v&(3) bonds in 2 are 0.019 and 0.030 A longer than the vA-0(2) and VB-O(2) bonds, respectively. This should be ascribed to the trans influence of Ob,though the extent is much less pronounced in comparison with that of the V02+ complex in 3. The O=V=O angle in V02+ complexes usually ranges from 103.5 to 107.5' and that in 3 lies within this range. In the O=V-L, type angle (L, = donor atom in the equatorial site), the 0(6)=V-0(5) and 0(6)=V-0(2) angles are always larger than the 0(6)=V-0(3) and 0(6)=V-N( 1) angles, respectively, throughout the three complexes. This indicates that the axial V=0(6) bond tilts toward the 0(3)--N( 1) edge in these three, irrespective of the environmental differences. The same tilt was also found in the pmida chelate,8 which is structurally very similar to [ VO(S-peida)(H,O)] , except that it has no methyl substituent. Such a tilt of the V=O bond in 1-3 as well as the pmida chelate means that the chelation of either ligand displaces the coordination sites in the idealized skeleton for the V02+ or V 0 2 + complex, owing to the strain characteristics of the pmida frame. Thus the chelation gives rise to a slant of the mean equatorial plane
( 1 1 ) Scheidt, W. R.; Collins, D. M.; Hoard, J. L. J . Am. Chem. SOC.1971, 93, 3873. (12) Scheidt, W. R.; Countryman, R.; Hoard, J. L. J . Am. Chem. SOC.1971, 93, 3878. (13) Fallon, G. D.; Gatehouse, B. M. Acta Crystallogr., Sect. B 1976,832, 71.
(14) Tachez, M.; Theobald, F.; Watson, K. J.; Mercier, R. Acta Crystallogr., Sect. B 1979, B35, 1545. (15) Oughtred, R. E.; Raper, E. S.; Shearer, H. M. M. Acta Crystallogr., Sect. B 1976, 832, 82. (16) Mathew, M.; Carty, A. J.; Palenik, G. J. J . Am. Chem. Soc. 1970, 92, 3197.
linear. wv-ob-v=o deviates slightly from the complete trans-planar structure, from which the VB=O bond is rotated clockwise about the VA+VB vector by 15.7 (2)'. The 0(3)-V-N(2)-C(9) segment in 3 is planar, the N(2)-C(6) and N(2)-C(7) bonds being disposed symmetrically with respect to the mean plane of this segment. This is not the case for the molecule in 1. The N(Z)-C ' C
Kojima et al.
1172 Inorganic Chemistry, Vol. 22, No. 8, 1983 Table VI. Bond Angles (deg) [ V,O, (9 peida) ] -
[VO(S-peida)(H,O)]
A
B
103.2 (1) 94.5 (1) 108.5 (1) 100.1 (1) 168.9 (1) 85.8 (1) 77.0 (1) 78.5 (1) 73.8 (1) 161.9 (1) 151.3 (1) 118.8 (2) 116.3 (3) 106.5 (3) 114.6 (3) 113.6 (3) 106.3 (2) 121.6 (2) 116.9 (3) 122.7 (4) 120.3 (4) 111.5 (3) 105.8 (2) 122.5 (2) 116.7 (3) 124.4 (4) 118.8 ( 3 ) 111.2 (3) 107.1 (1) 119.6 (3) 121.7 (4) 118.6 (5) 120.5 (4) 118.7 (4) 120.9 (4)
103.1 (2) 95.1 (2) 106.2 (2) 101.8 (2) 171.7 (2) 84.5 (2) 77.4 (2) 77.4 (2) 74.8 (2) 161.8 (2) 152.0 (2) 119.7 (4) 115.6 (5) 108.7 (4) 115.3 (5) 114.9 (5) 106.6 (3) 117.7 (4) 118.6 (5) 122.3 (5) 119.0 (5) 111.8 (5) 104.1 (3) 121.9 (4) 117.1 ( 5 ) 123.3 (5) 119.5 (5) 113.0 (5) 108.1 (3) 119.2 (5) 120.6 (5) 119.6 (7) 120.4 (7) 118.5 (6) 121.6 (6)
103.4 (2) 91.6 (2) 105.9 (2) 100.8 (2) 168.0 (2) 87.7 (2) 77.3 (2) 77.9 (2) 74.9 (2) 165.0 (2) 152.9 (2) 117.6 (4) 117.6 (5) 107.7 (4) 114.9 (5) 113.9 (5) 106.9 (3) 117.1 (4) 116.8 (5) 122.5 (5) 120.7 (5) 113.4 (4) 103.7 (3) 121.3 (3) 114.4 (5) 124.8 (5) 120.5 (5) 112.3 (5) 107.8 (3) 120.8 (5) 120.5 (6) 119.4 (7) 119.1 (7) 120.0 (6) 120.1 (6)
[ VO,(S-peida)]
105.7 (1) 88.8 (1) 106.7 (1) 98.4 (1) 163.1 (1) 90.2 (1) 75.1 (1) 76.8 (1) 74.9 (1) 165.2 (1) 150.7 (1) 118.2 (2) 114.8 (3) 107.5 (3) 116.0 (3) 114.7 (3) 105.1 (2) 117.2 (2) 116.5 (3) 123.5 (3) 120.0 (3) 110.7 (3) 101.3 (2) 120.4 (2) 117.9 (3) 125.0 (3) 117.1 (3) 113.7 (3) 112.2 (2) 119.5 (3) 121.7 (4) 119.0 (4) 119.6 (4) 118.9 (4) 121.2 (4)
179.5 (3)
against that in the idealized skeleton in which the V = O bond is probably perpendicular to the equatorial plane. The corresponding bond lengths and angles of the peida ligand themselves in 1-3 are almost in agreement with one another. The sole exception is that the C(10)-0(3) and C(10)-O(4) distances of the COO- group trans to O(5) in 3 are not much different from each other, in contrast to the significant difference between the C(8)-0(2) and C(8)-0( 1) distances of the COO- cis to the oxo ligand in 3 and 2. Similar trends are observed in (NH4)3[VOZ(oxalato)2]~2Hz09 and (NH&[ V O ( o x a l a t ~ )H~ 2( 0 ) ].HzO. l5 The differences in the two C-O bonds in these complexes are in the 0.021-0.024 A range when the COO- is trans to the oxo ligand, whereas they are in the 0.046-0.070 A range for the COO- cis to the oxo ligand. Strong trans influence of the V = O seems to diminish the polarization of the trans COO- group. Crystal Packing. Short contacts and hydrogen bonds in 1-3 are summarized in Table VII. In 1, all the H atoms of H,O,( 1) and ligating H20(5) participate in O-H.-O(O=C or OHz) hydrogen bonding, while one of the H atoms of Hz0,(2) does not. In 3, all the MeOH molecules are linked to the O(O=C) atom of the COO- group trans to the O(5) via the O H group (H--0(4)-.H = loso), while the Li+ ion approaches the O(O=C) of the COO- cis to the O(5) at a distance 1.968 A. The Li+ ion is surrounded tetrahedrally by two 0 atoms of the MeOH molecules, the O( l ) ( O = C ) of the "cis COO-", and the 0(6)(0-V) of the adjacent complex ion at the equivalent position (-x, y - 1/2, l/z - z ) , the Li+-.O distances ranging 1.926-1.968 A. (2) The halves of the dimer are very similar to each other in structure, but the surrounding of the A moiety is somewhat
Table VII. Short Contacts compd
A. * * B
dist, A 1.93 2.23 1.79 2.04 1.93 2.503 2.389 2.437 2.353 2.444 2.787 2.459 2.296 2.549 2.566 2.570
position of B
(8) (5)
(6) (5)
(6) (5)
(9) (6) (6) (5)
(6)
2.294 (6)
2.99 2.51 2.14 1.968 (7) 1.929 (8) 1.926 (8) 1.935 (7) 1.75 1.82
different from that of the B moiety as described below. Both > glycinato rings (V-N-CH,-COO) are located in one side of the mean plane of O=V-0,-V=O, while solely pyridine groups are present in the other side. Five Na' ions are dis1
V Complexes of [ [ 1 -(2-Pyridyl)ethyl]imino]diacetate
Inorganic Chemistry, Vel. 22, No. 8, 1983 1173
@
Figure 2. Stereoview showing the evironment of [V203(S-peida)2]-.Roman numerical superscripts for Na+ and C1 (in C104-) refer to the following equivalent positions: (I) 1 - x, y - 1/2, 1 - z, (11) x - 1, y, z - 1, (111) x - 1, y, z, and (IV) 1 - x, 1/2 + y , 1 - z for Na+; (I) 1 - x, y - 1/2, 1 - z and (11) 1 - x, 1/2 y, 1 - z for C1.
+
tributed in the glycinato side and are in contact with the carboxylato 0 and O(6A) atoms. On the other hand, three C10, anions are located in the pyridine side (Figure 2). The Na+-.O(OOC) distances are in the 2.294-2.787 A range, which is normal for Na+...O contacts. The C1’ atom is 6.862 (2) A away from the VA atom. C1 and C1” are 5.827 (2) and 6.453 A from the VB, respectively. Of the five Na+ cations, three are close to the A half, and two of the three C10, anions are located in the B side. The cation and anion distribution around the dimer indicates that the A moiety has more negative charge than the B moiety.
D
I
Discussion As described above, the two vanadium atoms are inequivalent in the mixed-valence dimer. Some of the bond lengths and angles around VA differ significantly from those around VP With the aim of comparing the coordination sites between V, and VB, the volumes of the coordination octahedra around the vanadium atoms were calculated to be 9.95 (2) and 9.58 (2) A3for the A and B octahedra, respective1 The corresponding volumes are 10.01 (2) and 9.62 (2) for [VO(Speida)(H20)] and [V02(S-peida)]-, respectively. The volumes of the A and B octahedra are thus close to those of the V(1V) and V(V) complexes, respectively. Furthermore, the deviation of V, from the [N(lA),O(2A),0(3A),O(5)] plane is equal to that of the V(1V) atom from the equatorial plane of [VO(S-peida)(H20)], and that of VB from the [N(lB),0(2B),O(3B),0(5)] plane is rather close to that of the V(V) atom in [V02(S-peida)]-. These structural features as well as the cation and anion distribution around the dimer strongly indicate that VA and V, are quadri- and quinquevalent in character, respectively. Hence, the mixed-valence dimer can be regarded as the class I1 ion of Robin and Day’s classification.” An attempt was made to investigate the XPS’s of 1-3 to obtain direct evidence for the oxidation states of the vanadium atoms in the dimer. However, these compounds decomposed under the experimental conditions for XPS
x.
(17) Robin, M.; Day,
P. Ado. Inorg. Chem. Radiochem. 1967,
10, 241.
I‘
b IO
20
30
(kK)
Wavenumber
Figure 3. Reflectance spectra of Na[V20,(S-peida)2].NaC104-H20 (a) and (NH4)9[V203(nta)21’3H20 (b).
measurement (the colors of 1-3 changed to brown). The reflectance spectrum of 2 shows peaks at 9400,13 900, 17400, and 26 800 cm-’ (Figure 3) and resembles its solution spectrum [lO200, ( E = l200), 13600 (940), 17700 cm-’ (470)] .3 There seems no large variation between the dimer structure in the solid state and that in solution. The absorption bands in 12 OO0-30000-cm~’ region are very similar in energy to those of 1 at 13 200 ( E = 27.4), 17 700 (16.4), and 28 200 cm-’ (357), which are assigned to d, d,, dyz,d, dz-p, and d, dz2 transitions, re~pectively.~However, the absorption of the dimer is much enhanced in comparison with that of 1. The reflectance spectrum of (NH4)3[V203(nta)2].3H20 is also presented in Figure 3. The nta complex has a structure similar to [V203[S-peida)J-, but the two vanadium atoms are reckoned to be equivalent at ambient temperature on the bases of solution ESR and crystallography.2 It has a crystallographically imposed center of symmetry, and the V-O,-V bond is completely linear and symmetric, but its
-
-
-
Znorg. Chem. 1983, 22, 1174-1 178
1174
symmetry can be approximated virtually to C2h. The reflectance spectrum of the S-peida dimer resembles that of the nta dimer in 9000-20 000-cm-' region. This indicates that these complexes have similar electronic structures, although the dimers in the former and latter are regarded crystallographically as class I1 and class I11 ions, respectively. The absorption around 10 000 cm-' is characteristic of the mixed-valence dimer. No such band is found in the uninuclear V02+ and V02+ complexes. The linearity and bond length in V-0b-v in these dimers indicate the presence of a multiple bonding. In the symmetric c z h dimer, the bonding in V-0b-v may be qualitatively described as follows. The py (0,) orbital participates in u bonding along with the dX2+ orbitals of two vanadium atoms (they axis parallels the V-0b-v bond). Both the px and pz orbitals of Ob are capable of coupling with metal d, and dyz to give ?r bonds, but the dxy-p,-d, set is energetically more favorable than the dyz-pz-dyzset. The bonding orbital in the former set (a,) accommodates two ?r electrons. The single d electron in this system may occupy the nonbonding b, orbital
mainly composed of the metal d, orbitals. The orbital of the nonsymmetric dimer corresponding to the nonbonding orbital in the symmetric dimer mainly consists of the d, orbital of the V, atom, since the d electron is virtually localized at the V, center as described above. The polarized charge distribution around the dimer seems to cause the localization of the electron. The absorption at 10000 cm-' in the symmetric dimer may arise from an electronic excitation from the nonbonding to antibonding (a,*) orbital. The antibonding orbital of the nonsymmetric dimer must have a greater contribution from the d, orbital of VB than that of V,, and in this sense the lowest energy absorption in the solid state may be regarded as a kind of intervalence-transfer transition.
-
Registry No. 1, 81898-97-7; 2, 84863-66-1; 3, 84894-05-3 Supplementary Material Available: Tables of observed and calculated structure factor amplitudes, hydrogen atom coordinates, and anisotropic thermal parameters (14 pages). Ordering information is given on any current masthead page.
Contribution from the Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
Solvent-Extraction Complexes of the Uranyl Ion. 2. Crystal and Molecular Structures of catena -Bis(p-di-n -butyl phosphato-0,O')dioxouranium(VI) and Bis( p-di-n -butyl phosphato-0 ,O')bis[ (nitrato) (tri-n -butylphosphine oxide)dioxouranium(VI)] J O H N H . BURNS
Received September 16, 1982 Two complexes of the uranyl ion with organophosphorus extractants have been analyzed by single-crystal X-ray diffraction methods. A polymeric complex, U02[(C4H9)2P04]2,is formed with dibutylphosphoric acid; and with a mixture of this acid and tributylphosphine oxide a dimeric complex having the composition (U02[(C4Hg)2P0,][(C4H9),PO]N03)2is formed. The first of these is triclinic, Pi,with a = 8.402 (6) A, b = 15.648 (9) A, c = 5.385 (3) A, a = 99.46 (4)O, 0 = 98.51 (4)O, y = 70.44 (3)O, and Z = 1; the second is also triclinic, Pi,with a = 13.510 (6) A, b = 13.741 (6) A, c = 10.055 (4) A, a = 121.32 (2)O, 0 = 100.28 (3)O, y = 80.00 (4)O, and 2 = 1 (dimer). In each structure, pairs of linear uranyl ions are bridged by two dibutyl phosphate ions. In one case the bridging is repeated indefinitely to form a polymer, and each uranyl ion has four 0 atoms about its equator. The other structure is dimeric, and the chain is terminated by NO3ions and phosphine oxide molecules at the equators of the uranyl ions.
Introduction A variety of organophosphorus compounds when dissolved in organic solvents are effective in extracting U(V1) from acidic aqueous solutions. In the liquid-liquid extraction process usually employed, the U022t ion moves from the aqueous phase to the organic as its aqueous solvation sphere is replaced by organophosphorus ligands to form extraction complexes. The structures of a number of these complexes are being studied in order better to understand the process of extraction. One such structure, previously reported,2 is that of U02(TBP0)2(N03)2,in which TBPO tri-n-butylphosphine oxide. Here the equatorial plane of the UOZz+ion contains no water but is occupied by two molecules of TBPO and two NO< ions. An analogous arrangement to this also exists in U02L2(N03)2 in cases where L = triethyl pho~phate,~ triisobutyl phosphate! and triphenylphosphine oxide.5 There is also the interesting question of why certain combinations of reagents are better extractants than either of the
'
(1) Blake, C. A., Jr.; Baes, C. F., Jr.; Brown, K. B. Znd. Eng. Chem. 1958,
50, 1163. (2) Part 1 : Burns, J. H. Znorg. Chem. 1981, 20, 3868. (3) Fleming, J. E.; Lynton, H. Chem. Znd. (London) 1960, 1415. (4) Burns, J. H.; Brown, G. M., unpublished results. ( 5 ) Alcock, N. W.; Roberts, M. M.; Brown, D. J . Chem. SOC.,Datron Trans. 1982, 25.
0020-1669/83/1322-1174$01.50/0
components alone (the so-called synergistic effectbs). Hence, in addition to the complex with TBPO mentioned above, a complex with di-n-butylphosphoric acid (HDBP) has been studied as well as a complex with a mixture of the two ligands. These latter two uranyl complexes are reported here. From these crystal structure analyses it can be seen how each component combines with the uranyl ion and what the result is of using a mixture of the two. Experimental Section Preparationof U02(DBP)2. Di-n-butylphosphoricacid was obtained from a mixture of mono- and dibutylphosphoric acids (Mobil Chemical Co., Richmond, VA) by dissolving the mixture in benzene and extracting out the monoacid with water. A 1:2 mixture of U02(N03)2-6H20and HDBP was heated to about 65 "C until it was liquid; in the process there were an evolution of brown oxides of nitrogen and the formation of tiny droplets of H 2 0 . The yellow liquid was desiccated over H 2 S 0 4and gradually crystallized as a mass of thin plates of UO,(DBP),. These bend easily or split into fibers, showing a mechanical property related to their polymeric structure. Preparation of U02(DBP)(TBPO)N0,. A 1:1:2 mixture of U02(N03)2-6H20, TBPO (Carlisle Chemical Works, Reading, OH), (6) Baes, C. F., Jr. Nucl. Sci. Eng. 1963, 16, 405. (7) Deane, A. M.; Kennedy, J.; Sammes, P. G. Chem. Znd. (London) 1960, 443. (8) Dyrssen, D.; Kuca, L. Acra Chem. Scand. 1960, 14, 1945.
0 1983 American Chemical Society
